PBS favorite and Harvard’s own Henry Louis “Skip” Gates Jr. (above) told reporters at this summer’s Television Critics Association press tour that he was inspired to investigate the history of African-Americans by a Bill Cosby documentary he saw on TV when he was 17 called “Black History: Lost, Stolen, or Strayed.” The profound impact that film had on Gates, he says, “shows the power of television.” He hopes to have a similar impact with this six-part chronicle that examines 500 years of African-American history, starting in the year 1513 and ending exactly 500 years later with Barack Obama’s reelection.

So far the penultimate season of this captivating saga of the Cali motorcycle club has been literally explosive, featuring a bunch of “oh no, they didn’t!” moments. From the big bang at the SAMCRO HQ, to the school shooting in the premiere, to the bloody deaths of several characters, including the eternally beleaguered Otto (played by “Sons” creator Kurt Sutter) it’s been a dark year for Jax (Charlie Hunnam) and the folks in Charming. While the extended episode lengths have sometimes revealed more gristle than meat, the cast has once again proven up to the task of telling these grim tales.

Brooklyn Nine-Nine 8:30 p.m., Fox

This crackerjack ensemble of this new cop comedy is gelling nicely but its secret weapon is the great Terry Crews.

NCIS 8 p.m., CBS

It’s throwback Tuesday with flashbacks to Tony’s past as a Baltimore cop. Apparently, he steered clear of Stringer Bell.